Angle-resolved photoemission study of untwinned PrBa${}_2$Cu${}_3$O${}_7$: undoped CuO${}_2$ plane and doped CuO${}_3$ chain

Abstract

We have performed an angle-resolved photoemission study on untwinned PrBa${}_2$Cu${}_3$O${}_7$, which has low resistivity but does not show superconductivity. We have observed a dispersive feature with a band maximum around ($\ddot{I}€$/2,$\ddot{I}€$/2), indicating that this band is derived from the undoped CuO${}_2$ plane. We have observed another dispersive band exhibiting one-dimensional character, which we attribute to signals from the doped CuO${}_3$ chain. The overall band dispersion of the one-dimensional band agrees with the prediction of $t-J$ model calculation with parameters relevant to cuprates except that the intensity near the Fermi level is considerably suppressed in the experiment.

6 pages, 10 figures